| abstract |
The beam guidance of a cathodically emitted and electron-optically focused electron beam, which is subjected to energy selection in a cylindrical capacitor (1) and finally strikes a detector (12), is improved in that the electrons in the plane perpendicular to the cylindrical capacitor axis admittedly affect the Input aperture (3) of the capacitor (1), but perpendicular to it, but focused on the detector (12), which is achieved by an appropriate design of the emission and bundling systems (5 to 10). When using this type of beam guidance in electron impact spectrometers with cylindrical capacitor deflection units (1, 2) results in a high energy resolution with a high signal current, which significantly improves the spectrometer with cylindrical capacitor deflection, which is particularly favorable in terms of manufacture and handling, compared to the previously preferred devices with spherical capacitor or cylindrical mirror deflection. A particularly interesting implementation possibility is an appropriately designed repeller focusing surface (7 ') with different radii of curvature (r i , r 2 ) together with a coordinated lens system (8 to 1 0 ). A graphite coating of the beam guiding elements brings additional advantages. |